Provided by: postfix_3.0.4-5build1_i386 bug


       flush - Postfix fast flush server


       flush [generic Postfix daemon options]


       The flush(8) server maintains a record of deferred mail by destination.
       This information is used to improve the performance of  the  SMTP  ETRN
       request,   and  of  its  command-line  equivalent,  "sendmail  -qR"  or
       "postqueue -f".  This program expects to  be  run  from  the  master(8)
       process manager.

       The record is implemented as a per-destination logfile with as contents
       the queue IDs of deferred  mail.  A  logfile  is  append-only,  and  is
       truncated when delivery is requested for the corresponding destination.
       A destination is the part on the right-hand side of the right-most @ in
       an email address.

       Per-destination  logfiles  of  deferred  mail  are  maintained only for
       eligible destinations. The list of eligible destinations  is  specified
       with  the fast_flush_domains configuration parameter, which defaults to

       This server implements the following requests:

       add sitename queueid
              Inform the flush(8) server that the message with  the  specified
              queue ID is queued for the specified destination.

       send_site sitename
              Request  delivery  of  mail  that  is  queued  for the specified

       send_file queueid
              Request delivery of the specified deferred message.

              Refresh non-empty per-destination logfiles that were not read in
              $fast_flush_refresh_time hours, by simulating send requests (see
              above) for the corresponding destinations.

              Delete empty per-destination logfiles that were not  updated  in
              $fast_flush_purge_time days.

              This request completes in the background.

       purge  Do a refresh for all per-destination logfiles.


       The  flush(8) server is not security-sensitive. It does not talk to the
       network, and it does not talk to local users.  The  fast  flush  server
       can run chrooted at fixed low privilege.


       Problems and transactions are logged to syslogd(8).


       Fast flush logfiles are truncated only after a "send" request, not when
       mail is actually delivered, and therefore can  accumulate  outdated  or
       redundant data. In order to maintain sanity, "refresh" must be executed
       periodically. This can  be  automated  with  a  suitable  wakeup  timer
       setting in the configuration file.

       Upon  receipt of a request to deliver mail for an eligible destination,
       the flush(8) server requests delivery of all messages that  are  listed
       in  that  destination's  logfile, regardless of the recipients of those
       messages. This is not an issue for mail that is sent to a relay_domains
       destination  because  such  mail  typically  only has recipients in one


       Changes to are picked up automatically  as  flush(8)  processes
       run for only a limited amount of time. Use the command "postfix reload"
       to speed up a change.

       The text below provides only a parameter summary. See  postconf(5)  for
       more details including examples.

       config_directory (see 'postconf -d' output)
              The  default  location  of  the  Postfix  and
              configuration files.

       daemon_timeout (18000s)
              How much time a Postfix daemon process  may  take  to  handle  a
              request before it is terminated by a built-in watchdog timer.

       fast_flush_domains ($relay_domains)
              Optional   list   of   destinations   that   are   eligible  for
              per-destination logfiles with  mail  that  is  queued  to  those

       fast_flush_refresh_time (12h)
              The  time  after  which  a  non-empty but unread per-destination
              "fast flush" logfile needs to be refreshed.

       fast_flush_purge_time (7d)
              The time after  which  an  empty  per-destination  "fast  flush"
              logfile is deleted.

       ipc_timeout (3600s)
              The  time  limit  for  sending  or receiving information over an
              internal communication channel.

       max_idle (100s)
              The maximum amount of time that an idle Postfix  daemon  process
              waits for an incoming connection before terminating voluntarily.

       max_use (100)
              The maximal number of incoming connections that a Postfix daemon
              process will service before terminating voluntarily.

       parent_domain_matches_subdomains (see 'postconf -d' output)
              A list of Postfix features where the pattern ""  also
              matches  subdomains  of,  instead  of  requiring an
              explicit "" pattern.

       process_id (read-only)
              The process ID of a Postfix command or daemon process.

       process_name (read-only)
              The process name of a Postfix command or daemon process.

       queue_directory (see 'postconf -d' output)
              The location of the Postfix top-level queue directory.

       syslog_facility (mail)
              The syslog facility of Postfix logging.

       syslog_name (see 'postconf -d' output)
              The mail system name that is prepended to the  process  name  in
              syslog   records,   so   that   "smtpd"  becomes,  for  example,


       /var/spool/postfix/flush, "fast flush" logfiles.


       smtpd(8), SMTP server
       qmgr(8), queue manager
       postconf(5), configuration parameters
       master(5), generic daemon options
       master(8), process manager
       syslogd(8), system logging


       Use "postconf readme_directory" or "postconf html_directory" to  locate
       this information.
       ETRN_README, Postfix ETRN howto


       The Secure Mailer license must be distributed with this software.


       This service was introduced with Postfix version 1.0.


       Wietse Venema
       IBM T.J. Watson Research
       P.O. Box 704
       Yorktown Heights, NY 10598, USA